Participação do sistema renina angiotensina na função cardiovascular de ratos recém-desmamados sob tratamento crônico com frutose e sobrecarga salina
Data
2014-08-31
Autores
Araujo, Iara Cristina de 
Orientadores
Farah, Vera de Moura Azevedo
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Estudos relacionam o crescente aumento de incidência da síndrome metabólica com o aumento do consumo de frutose e sal na dieta da população, fatores estes que aumentam o risco para doenças cardiovasculares, consideradas como uma das principais causas de mortes em todo o mundo. Sabe-se que o Sistema Renina Angiotensina (SRA) é um complexo e importante sistema hormonal para ajustes homeostáticos atuando como um mecanismo de conservação de cloreto de sódio e da regulação da pressão arterial (PA), onde fatores externos influenciam o mesmo, alterando as vias de formação de seus componentes. Desse modo, o objetivo do presente estudo foi avaliar o efeito da sobrecarga salina de 2% na função cardiovascular em um modelo experimental de síndrome metabólica induzida por frutose e investigar o papel do sistema renina angiotensina tecidual. Ratos Wistar machos, recém-desmamados, (50-60g) foram separados em 4 grupos experimentais (n?4): controle (C), sal (S), frutose (F), e frutose sal (FS). Os principais resultados obtidos foram: 1) redução do peso corporal nos grupos tratados com sal; 2) aumento da deposição de gordura retroperitonial e epididimal em F e redução no grupo S; 3) intolerância a sobrecarga de glicose nos grupos S,F e FS; 4) aumento da PA nos grupos S,F e FS associado a diminuição da FC do grupo S; 5) aumento na atividade da ECA no rim do grupo S em relação ao grupo C; 6) aumento da formação das angiotensinas I, II, 1-7 nos grupos F, FS. Assim sendo, nossos resultados sugerem que o SRA pode participar na gênese da hipertensão arterial induzida pela frutose, ao passo que o tratamento com sal utiliza outros mecanismos para o aumento da PA e que o aumento da formação de Ang1-7 atua como mecanismo protetor para o organismo. Além disso, a combinação dos fatores de risco, frutose e sal, promoveu um quadro de disfunções diferenciadas nos componentes do SRA podendo justificar pelo menos em parte as alterações metabólicas, como no peso corporal, glicemia de jejum e intolerância à glicose, e cardiovasculares observadas nos grupos experimentais.
Studies described the growing incidence of metabolic and cardiovascular disorders in population with increased fructose and salt consumption. These two factors are associated with increased risk of cardiovascular diseases, considered one of the leading causes of death worldwide. It is known that Renin Angiotensin System (RAS) is a complex hormonal system that acts on homeostatic aiding in homeostasis by acting as a mechanism for sodium chloride retention and regulating blood pressure, where external factors influencing the system change the means of formation of its components. The aim of this study was to investigate the effect of saline overload 2% during 10 days on cardiovascular function in an experimental model of metabolic syndrome induced by chronic fructose consumption postweaning and to investigate the role of RAS in the kidney and heart tissue. Male Wistar rats, weanling (50-60g) formed 4 groups: control (C), salt (S), fructose (F), fructose and salt (FS). The main results were: 1) reduction in body weight in the groups treated with salt; 2) increase of retroperitoneal and epididymal fat deposition in F group and a reduction in S group; 3) glucose intolerance in S, F, FS groups; 4) increased blood pressure in treated groups S, F, FS followed by decreased heart frequency in Salt group; 5) increase of ACE activity in the kidney for S group when compared to C; 7) increased formation of angiotensin I, II, 1-7 in fructose treated groups (F, FS). Thus, our results suggests that RAS assists in the genesis of hypertension induced by fructose, while salt uses different mechanisms that assist in the hypertension induction, and the increased formation of Ang1-7 related to salt could be a protective mechanism for the organism. Moreover, the combination of risk factors, fructose and salt, promoted a framework for different disorders in RAS components that can justify at least in part the metabolic changes such as body weight, fasting glucose and observed in cardiovascular parameters in the experimental groups.
Studies described the growing incidence of metabolic and cardiovascular disorders in population with increased fructose and salt consumption. These two factors are associated with increased risk of cardiovascular diseases, considered one of the leading causes of death worldwide. It is known that Renin Angiotensin System (RAS) is a complex hormonal system that acts on homeostatic aiding in homeostasis by acting as a mechanism for sodium chloride retention and regulating blood pressure, where external factors influencing the system change the means of formation of its components. The aim of this study was to investigate the effect of saline overload 2% during 10 days on cardiovascular function in an experimental model of metabolic syndrome induced by chronic fructose consumption postweaning and to investigate the role of RAS in the kidney and heart tissue. Male Wistar rats, weanling (50-60g) formed 4 groups: control (C), salt (S), fructose (F), fructose and salt (FS). The main results were: 1) reduction in body weight in the groups treated with salt; 2) increase of retroperitoneal and epididymal fat deposition in F group and a reduction in S group; 3) glucose intolerance in S, F, FS groups; 4) increased blood pressure in treated groups S, F, FS followed by decreased heart frequency in Salt group; 5) increase of ACE activity in the kidney for S group when compared to C; 7) increased formation of angiotensin I, II, 1-7 in fructose treated groups (F, FS). Thus, our results suggests that RAS assists in the genesis of hypertension induced by fructose, while salt uses different mechanisms that assist in the hypertension induction, and the increased formation of Ang1-7 related to salt could be a protective mechanism for the organism. Moreover, the combination of risk factors, fructose and salt, promoted a framework for different disorders in RAS components that can justify at least in part the metabolic changes such as body weight, fasting glucose and observed in cardiovascular parameters in the experimental groups.
Descrição
Citação
ARAUJO, Iara Cristina de. Participação do sistema renina angiotensina na função cardiovascular de ratos recém-desmamados sob tratamento crônico com frutose e sobrecarga salina. 2014. Dissertação (Mestrado) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2014.